Penny shows yearning to follow a tribesman (6)
I believe the answer is:
apache
'tribesman' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'penny shows yearning to follow a' is the wordplay.
I cannot quite understand how this works, but
'penny' could be 'p' (short for pence) and 'p' is found within the answer.
'yearning' could be 'ache' (I've seen this before) and 'ache' is found in the answer.
'a' is found in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for apache that I've seen before include "Parisian ruffian - Indian" , "Indians" , "ruffian in capital of France" , "A native N. American people" , "North American native tribe" .)